Calculate the ΔG°rxn using the following information. 2 H2S(g) + 3 O2(g) → 2 SO2(g) + 2 H2O(g) ΔH°f(kJ/mol) -20.6 296.8 -241.8 S°(J/mol∙K) 205.8 205. 248.2 188.8 ΔG°rxn = ?
| +676.2 kJ | |
| +108.2 kJ | |
| -466.1 kJ | |
| +196.8 kJ | |
| -147.1 kJ |
In: Chemistry
Propose a buffer system using ascorbic acid. Explain how this solution can protect against acids and bases, specifically.
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Compare the deltaS fusion with the deltaS vaporization for water. Are they reasonable in terms of the relative disorder of the states of matter?
deltaH fusion= 6.10 kJ/mol and deltaH vap= 40.7 kJ/mol
In: Chemistry
Write balanced net ionic equations for the following reactions in basic solution:
H2O2(aq)+Cr2O2−7(aq)⟶O2(g)+Cr3+(aq)
Express your answer as a balanced net ionic equation. Identify all of the phases in your answer.
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a. Assuming that glucose and water form an ideal solution, what is the partial pressure of water at 20o C of a solution of 1.00 g of glucose (mol wt 180 g/mol) in 100 g of water? The vapor pressure of pure water is 2338 Pa at 20o C.
b. What is the osmotic pressure, in Pa, of the solution in part (a) versus pure water?
c. What would be the osmotic pressure, in Pa, of a solution containing both 1.00 g of glucose and 1.00 g of sucrose (mol wt 342) in 100 g of water at 20o C?
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What is the pH of 50 ml of a 0.10M weak acid (Ka =1.0x10-5) plus 50ml water?
What is the pH of 50 ml 0.010M weak base plus 100ml water ? Kb =1.0x10-5.
What is the pH of a solution, which is 0.10M in a weak acid, HA and 0.2M in NaA? Ka =1.0x10-5In: Chemistry
Electronic configurations follow from the principle quantum numbers n, l, m, and s. What is the relationship with n and the periodic table? What is the relationship with n and the number of valance electrons? The ‘l ’ quantum number designates the type of orbital. What is an orbital? Do electrons have to stay in their designated orbital? The ‘m’ quantum number gives the degeneracy of the orbital type. Is there a difference in the px and py orbitals? Why does the spinning of the two electrons sharing an orbital have to be opposite. Are electrons really spinning?
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Balance the following oxidation-reduction reactions using the half-reaction method.
a) S2-(aq) + NO3-(aq) ---> S8(s) + NO2(g) acidic solution
b) MnO4-(aq) + I-(aq) ---> MnO2(s) + IO3-(aq) basic solution
c) Sb(s) + H2SO4(aq) ---> Sb2(SO4)3(s) + SO2(g) acidic solution
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1) Sort the phrases pertaining to pure substances and mixtures as either true or false. Note: If any part of this question is answered incorrectly, a single red X will appear indicating that one or more of the phrases has been placed incorrectly.
a)pure substances cnnot be separated by physical means.
b) homogeneous mixtures have unifform properties throughout.
c) the components of homogeneous and heterogeneous mixtures cannot be separated.
d) components of a homogeneous mixture are visibly distinct.
e) heterogeneous mixtures contain more than one part, and each part has its own properties.
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A 110.0 −mL buffer solution is 0.110 M in NH3 and 0.135 M in NH4Br.
Part A What mass of HCl could this buffer neutralize before the pH fell below 9.00? Express your answer using two significant figures.
m=?
Part B If the same volume of the buffer were 0.265 M in NH3 and 0.390 M in NH4Br, what mass of HCl could be handled before the pH fell below 9.00? Express your answer using two significant figures.
m=?
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What is the difference between absorption and emission? Transmission and reflection?
When plotting a graph of A vs. B, what does it mean if one says that A is directly proportional to B? What would the graph look like?
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NAD^+(aq)+2H^+(aq)+2e^- --> NADH(aq)+H^+(aq) E= -0.320V
Oaloacetate^2-(aq)+2H^+(aq)+2e^- --> malate^2-(aq) E= -0.166V
a. Calculate the standard potential for the following reaction: Oxaloacetate^2- (aq) +NADH(aq)+H^+(aq) --> malate-(aq)+NAD^+(aq)
b. Calculate the equilibrium constant for the reaction at 298K
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The Na –glucose symport system of intestinal epithelial cells couples the \"downhill\" transport of two Na ions into the cell to the \"uphill\" transport of glucose, pumping glucose into the cell against its concentration gradient. If the Na concentration outside the cell ([Na ]out) is 163 mM and that inside the cell ([Na ]in) is 23.0 mM, and the cell potential is -51.0 mV (inside negative), calculate the maximum ratio of [glucose]in to [glucose]out that could theoretically be produced if the energy coupling were 100% efficient. Assume the temperature is 37 °C.
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If the same volume of the buffer were 0.265 M in NH3 and 0.390 M in NH4Br, what mass of HCl could be handled before the pH fell below 9.00?
Two sig. figs.
m= ?
In: Chemistry
For a molecule of fluorous acid, the atoms are arranged as HOFO. (Note: In this oxyacid, the placement of fluorine is an exception to the rule of putting the more electronegative atom in a terminal position.) What is the formal charge on each of the atoms? Enter the formal charges in the same order as the atoms are listed. Express your answers as charges separated by comma. For example, a positive one charge would be written as +1.
In: Chemistry